If you are using Skyla, you should replace it after three years (viaPlanned Parenthood).

Kyleena can be used for five years, and both Mirena and Liletta should be replaced after eight years.

If you are using Paragard, however, it technically does not need to be replaced for twelve years.

patient and doc

All of these reasons are perfectly valid and require a call to your doctor.

A doctor showing an IUD to a patient

A doctor on the phone